A known method for producing a porous metal body having a high porosity and a large surface area is a method in which a metal layer is formed on a surface of a porous resin body such as a resin foam. For example, Japanese Unexamined Patent Application Publication No. 11-154517 (PTL 1) describes a method for producing a porous metal body, the method including subjecting a porous resin body to an electrical conduction treatment, forming an electroplating layer formed of a metal on the porous resin body, and optionally removing the porous resin body by incineration.
Japanese Unexamined Patent Application Publication No. 2012-132083 (PTL 2) proposes a porous metal body formed of a nickel-tin alloy as a porous metal body having oxidation resistance, corrosion resistance, and a high porosity and suitable for a current collector for a battery, a capacitor, a fuel cell, or the like. Furthermore, Japanese Unexamined Patent Application Publication No. 2012-149282 (PTL 3) proposes a porous metal body formed of a nickel-chromium alloy as a porous metal body having high corrosion resistance.